DENVER -- Top officials with Denver Public Schools returned to the bargaining table Sunday morning, but as expected, the teachers union negotiators failed to arrive on the eve of expected strike in the state's largest school district.

On Saturday night, negotiations broke apart and the Denver Classroom Teachers Association said its members will go on strike beginning Monday.

The union said it won't negotiate again until Tuesday, after the strike is expected to be in full force. It would be the first teachers strike in Denver Public Schools, the largest district in the state, since 1994.

The sides have been negotiating for months. Discussions escalated in January, when the pay agreement between the union and district expired.

The union voted overwhelmingly in January in favor of a strike as teachers seek increased pay and a decrease on teachers' reliance on one-time bonuses.

On Wednesday, the state declined to intervene in the negotiations, clearing the way for a strike.

Denver Public Schools negotiators, led by Superintendent Susana Cordova, offered a new plan Saturday with $23 million in funding for teachers.

That is $2.5 million more than the previous offer, but $5.5 million short of what the union is demanding.

The money would come from the elimination of about 150 positions with Denver Public Schools' central office.

Cordova also said she is committed to eliminating performance-based bonuses for central office employees.

"I think it's incredibly disappointing," Cordova said Sunday. "Our governor has said this, our mediator has this, this ends with a deal. And the whole question is, is it going to end with a deal before there's a strike or after there's a strike?

"I think the most important thing we can do is get to work and I'm not sure I understand why they think we should wait until Tuesday. So I'm very disappointed.

"Negotiating is trying to get closer to the middle. We've moved way past the middle. We've made enormous changes based on their feedback. It may not be exactly the way they'd like to see it, but I don't think you can say that we haven't tried to address the concerns we've raised."

Cordova said Saturday that schools will be open on Monday, but early childhood education programs will be closed.

Denver Public Schools enrolls about 92,000 students and has about 5,600 teachers.